1. Field of the Invention
The present invention relates to radiographic imaging, and more particularly to an improved apparatus and process for digitally retrieving information projected onto a reusable radiographic film and for erasing and restoring the radiographic film immediately after retrieval and in the same assembly.
2. Description of the Prior Art
Traditional x-ray imaging systems using silver-based films are being replaced by radiographic imaging systems using photo-stimulable phosphor imaging films or substrates eliminating the need for physical storage of the imaged film since digital retrieval of the image information includes input and computer storage permitting viewing of such information on a viewer, such as CRT tube assembly. Additionally, such computer stored image information permits facile electronic transmission to any preselect location obviating physical transfer of the thus formed image on the imaging film.
In U.S. Pat. No. 5,874,744 to Goodman, et al., assigned to the same assignee as the present invention, there is disclosed a process and apparatus for processing radiographic information from an anisotropic storage phosphor screen including an opto-electro-mechanical assembly to achieve faster scan of an interrogating beam and including detector and computer assembly, herein incorporated by reference.
In U.S. Pat. No. 6,599,014 to Thoms, there is disclosed an assembly for reading flexible storage films wherein the flexible storage film having image-wise projected information is positioned on a cylindrically-shaped surface and is caused to be linearly moved there over while being interrogated or scanned via a slot by a light beam generated in a helical line in a continuous manner from a point disposed at the axis of the cylindrically-shaped surface. The output fluorescence light or signal generated at the actual point the light beam intersects the storage film is received by a large diameter photomultiplier tube disposed proximate the slot. Such output signal is recorded together with positioning encorders to obtain an electrical image of the thus stored x-ray image on the storage foil. The configuration of the photomultiplier and the distance there from to the interpreting electronics results in a signal/noise ratio which while acceptable if advantageously decreased would provide more efficacious end result.
As used herein, the term “reusable storage film” is a flexible substrate formed with a layer of a photo-stimulable phosphors which is capable of imaging with ionizing radiation or x-rays which after imaging may be interrogated or scanned with a source of light energy to produce photo-stimulated luminescence information capable of being digitally read and stored.